This invention relates to a seat adjuster or track assembly for supporting a vehicle seat for selective back and forth adjustment in the passenger compartment of the vehicle.
Typically, the front seat of a vehicle is supported by two adjustable track assemblies, there being one track assembly beneath the seat along each side thereof. Each assembly includes an upper track secured to the lower side of the seat and supported on a lower-track to move back and forth in the passenger compartment. The lower track is anchored to the floor pan of the vehicle.
In modern seat adjusters, a seat belt anchor is attached to the rear end portion of the upper track, usually by means of a bracket, and serves as an anchor point for the strap of a seat belt. As a result of anchoring the seat belt to the upper track, the seat belt adjusts back and forth with the seat so as to increase the comfort of the passenger. When a frontal crash occurs, however, the upwardly and forwardly directed load imposed by the passenger against the seat belt is transmitted to the upper track and tends to move the upper track upwardly and forwardly relative to the lower track. Movement of the upper track relative to the lower track must be restrained during a crash in order to reduce the chances of passenger injury. In manually adjustable track assemblies, the selectively operable latch which normally holds the seat in a fixed position also restrains forward movement of the seat during a crash.
The present invention more particularly relates to a power-operated seat adjuster in which back and forth adjustment of the seat is effected by an electrically operated motor. Power-operated seat adjusters are not equipped with selectively operable latches for holding the seat in a fixed position and thus other means must be provided for restraining movement of the seat during a crash.